Note: Descriptions are shown in the official language in which they were submitted.
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- 1 - C.1046
DE~ERGE~T COMPOSI~IO~
ECH~ICA~ FT~Ln . ~ . .
~ he ~resent invention relates to detergent compositions
in partieulate or bar form whieh are adapted for fabrie .
washing. he invention eoneerns in partieular sueh
eompositions whieh æ e suitable for washing by hand in
eool, ie eold or lukew æ m water, as oceurs widel~ in .
so-.ealled developing countries and low eost formulations
. for usè in developed countries~
~AC~GROUND AR~
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A-major problem in formulating detergent products for
- fabrie.washing by hand and in cool water, is the~di~fieulty
in reconciling the need for a hi.ghl~ e~fec-tive detergency
builders system which will ade~uately soften water during
use under adverse washing eonditions, which often also
inelude low product dosage, wi-th the fact that the users
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of such compositions cannot in general afford the most
effective systems which would otherwise be desired. ~or
indeed do the economies of the developing countries always
permit the importation of large tonnages of foreign
detergency builder materials such as sodium tripol~phosphate.
I-t has been proposed previously to use sodium carbonate
as a detergency builder, and this material is widely
available and relatively cheap. Unfortunatel~, hot~ever,
sodium c æbonate when used alone as the detergency builder
does not function so effectively as would be desired,
particularly at cool washing temperatures. Although the
level of calcium ion concentration is lowered to a
sufficient level by the presence of sodium c æbonate, ie
by precipitation of calcium c æbonate, the precipitation
process is-a slow one and during the e æ ly part of the
wash cycle the calcium concentration is higher than is
desired for effective washing. During the initial period `
before the sodium carbonate is fully effective, there can
be interaction between the calcium ions present and other
ingredients in the detergent compositions. For example
anionic detergent surfactants such as some sodium alkyl
benzene sulphonates can be precipitated in the form of the
calcium salts and this therefore contributes to a further
reduction in detergenc~. Other types of detergent
surfacta~ts æ e known which are~not precipitated by calcium
ions, for example nonionic detergent surfactants, but these
more sophisticated detergent surfactants tend to be more
expensive, which mitigates against their use in the
relatively cheap formulations.
DISC~OSURE OF ~HE INVE~IO~
~ he present invention seeks to provide a way of
improving the effectiveness of sodium `i~c æbonàte as a
detergency builder, particularly under adverse washing
circumstances, but~without imposing a heavy cost burden on
the compositions. ~his has been achieved ~y including a
low level of pyrophosphate salt in the compositions.
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According to the present inven-tion, there is provided
an alkaline detergent composition for fabric washing
comprising a detergent surfactant and an alkali metal
carbonate, containing
( i) from about 10% to about 40% of a synthetic-anionic,
nonionic, ampho-teric or zwitterionic de~ergent
surfactant or a mixture thereof;
( ii) from about 10% to less than about 40% of an alkali
metal carbonate;0 (iii) from about 1% to about 12% of a pryophosphate material
selected from ammonium, sodium and potassium pyro-
- `phosphates; and ~ `
( iv) not more than about 5% of other phosphate builder salt~
all percentages being by weight of ~he composition. ~he
composition may be in powder form or in the form of a laundry
bar.
It has been ~ound that the addition of the py~ophos-
phate material together with the alkali metal carbonate
achieves a much more cost-effective building perfcrmance
tha~ either of the materials would do alone. It appears
that the presence of the low level of pyrophosphate makes
the calcium ion concentration drop ver~ quickl~ to`a
satisfactory low level, after which the sodium carbonate
maintains the calcium ion concentration at the low level.
~he resultant detergent compositio~s are cheaper because
of the unsophisticated builder s~stem~, and yet give satis-
factor~ detergen;cy under the ad~erse washing conditions.
BE~l MODE 0~ C~RRYING OUl I~VE~I0~
- ~he pyrophosphate material used may-be either
30 potassium or preferably~sodium pyrophosphate, as the ;~
latter is cheaper and more readil~ available.~ ~ormall~
the tetraaIkali metal salts are used, but the partially
neutralised alkali metal salts could be used`if~`desired to
form the compositions. In the latter event other more ~
alkaline salts would also be present to main-tai~ a high pH
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in the end product, with full neutralisation to the tetra
alkali metal pyrophospha-te salts. ~he alkali metal pyro-
phosphate can be used initially as the anhydrous or hydrated
salts, but it is preferred tha-t the salts should be at
least partially hydrated in the final detergent compositions,
either by initial~use of the hydrated salts or by hydration
during powder production~ ~he amount of the alkali metal
pyrophosphate salt is calculated in anhydrous form and is
preferably about 2% to about 10% by weight of the
composition.
Advantageously, the amount of phosphorus in the ~
formulation, in the form of the pyrophosphate, is from
about 0.5% to about 2.5%.
Some other phosphate builder salts may be present at
low levels, eg not exceeding about 5% by weight o~ the
composition, although this is not normally desired. ~ow
levels of other phosphates are commonly present as
impurities in the alkali metal p~rophospha-tes supplied,
so the presence of the other phosphates may in practice
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be unavoidable. ~uch other phosphate builder salts include
in particular sodium tripolyphosphate and sodium ortho-
phosphate and the corresponding potassium-salts when
potassium pyrophosphate is used.
~he alkali metal carbonate salt used may be potassium
25` or preferably sodium carbonate or a mixture thereof. ~he
carbonate sal-t is generally fully neutralised, bu-t it may
co~tain some potassium or sodium bicarbonate or sesqui-
carbonate. Alkali metal percarbonates may also be used.
lhe amount of the alkali metal c æbonate used can be
v æ ied between about 10% and about 40% by weight of the
compositions but it is preferred to use an amount of about
15% to about 30% by weight, and at least about 10% of the
carbonate must be fully neu-trallsed, based on the weight
of the composition. ~he amou~t~of the alkali metal
carbonate is determined on an anhgdrous basis, although
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the carbonate salt may be hydrated before or during
detergent production. ~he amount of bicarbona~e can be
up to about 20% b~ weight of -the composition, which is
equivalent to up to about 40% of ses.quicarbonate, but i-t
is preferred to have a bicarbonate content of about 5%
to about 15% of the composition.
~he detergent composi-tions must include from about
10% to about 40% by weight of a synthetic detergent
s.urfactant. It is preferred to have a relatively high
level of detergent surfactant present in the compositions,
that is at least about 20% b~ weight of the composition~
as this facilitates the production of adequate lather
levels' under the conditions of usage. in the developing
cou~tries, generally with a maximum level of about 30%.
15 for reasons of cost.
.
- It is preferred to include a higher amount of
- - sy~thetic detergent surfactant when the total amount
' o~ carbonate, pyrophosphate a~d other phosphate builder
salts, if present, is lower and conversel~ the amount
~'..`20 o~ synthetic detergent surfactant can be reduced when
the total amount of builder salts is increased. ~hus,
it is preferred that the total amount of s~nthetic
detergent surfactant, alkali metal car~onate, p~rophos-
phate material and other phosphate'builder salts when :'
25 . p~esent èxceeds about 30%9 and is preferabl~ more''than
about 40% by weight of the composition.
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It is particularly preferred to use an anionic detergent
sur~actant as these tend to be cheaper and more readily
a~ailable in developing countries. ~he alkali metal alkyl
benzene sulphonates, especially sodium linear secondary
aIkyl (C10-C15) benzene sulphonate, are particularly
preferred. However, other anionic detergent surfactants
which are`generally water-soluble alkali metal salts o~
organic sulphates and sùlphonates ha~ing alkyl radicals
containing from about 8 to 22-c æbon atoms may be employed.
~10 ~xamples of such other anionic detergent surfactants are
sodium and potassium alkyl'sulphates, especiall~ those
obtained by sulphating higher`(C8-C18)-alcohols produc~d
for example from tallow or coconut oil; sodium alk~l
glyceryl ether sulphates, especialIy those ethers of the
;15 higher alcohols derived from tallow or coconut oil and
synthetic alcohols derived from petroleum; sodium coconut
oil fatty acid monoglyceride sulphates and sulpho~ates; `
sodium and potassium salts o~'sulphuric `acid esters of
higher (C8-C18) fatty al'cohol-alkylene oxide, particularly
eth~lene oxide, reaction products; the reaction products ~
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of fat-ty acids such as coconut fatty acids esterified with
isethionic acid and neutralised with sodium hydroxide;
sodium and potassium salts of fa-t-ty acid amides of methyl
taurine; alkane monosulphonates such as those derived by
reacting alpha-ole~ins (C8-C20) with sodium bisulphite and
then hydrolyising with a base to produce a random
sulphonate; and olefin sulphonates, which -term is used to
describe the material made by reacting ole~ins, particularly
C~-C20 alpha olefins, with ~03 and then neutralising and
h~drolysin~ the reaction praduct.
~ onionic detergent surfactants may be used in the
detergent compositions although this is not generally
desired becàuse of their relati~ely high-cost and because
they tend to result in decreased lather properties.
Howaver, they may be used to give a boost to detergency
properties at relatively low lavels of for example up to
about 5% of the composition. ~he nonionic detergent
sur~ac-tants are the reaction products of-compounds having
hydrophobic groups and a reactive hydrogen atom, for
example aliphatic alcohols, acids~ amides or aIk~l penols
with alkylene oxides, especially ethylene oxide either
alone or with propylene oxide. ~pecific nonionic
detergent surfactants are alkyl (C6-C22) phenol-ethylene
oxide condensates, generally 5 to 25 EO7 ie 5 to 25 units
o~ ethylene oxide per molecule; the candensation products
of aliphatic (C6-C18) primary or secondary linear or ~`
branched alcohols with ethylene oxide, generall~y 6 to`30 EO
and productsmade by condensation of ethylene oxide with the~
reaction products or propylene oxide and ethylenediamine. `
Other so-called nonionic detergent surfactants include
long chain te~tiary amine oxides, long chain -tertiary
phosphine oxides and dialkyl sulphoxides~ Mixtures of
amine oxides with ethoxylated nonionic compounds can also
` be used.
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Amounts of amphoteric of zwit-terio~ic detergent
surfactants may also be used in the'compositions of the
invention but this is no-t normally desired due to their
relatively high cost. If any amphoteric or zwitterionic
detergent surfac-tants are used it is generally in small
amounts in compositions based on the much more commonly
used syntheticanionic and/or nonionic detergent surfactants.
Apart from the essen-tial detergent surfactants, and
detergency builders? the detergent compositions of the
invention can contain any of the conventional additives a-t
the levels such materials are normally employed in fabric
washing detergent compositions. However, the need to
control the cost of products may in practice preclude the
use of more expensive additives. Moreover, the washing
conditions employed, particularl~ hand washing in cool
water, make it less practical to use lather depressa~ts,
oxygen-based bleaching agents such as sodium perborate and
sodium perc æbonate with or without peracid bleach
precursors, or enz~mes such as proteases and amylases~
However, ~here difference washing conditions are used, such
as machine washing at moderate or high temperaturesj such
additives will generally~be included in the compositions,
in particular from about 10% to about 50yo of a peroxygen
bleach. ~he additives which æ e more commonly used in
detergent compositions suitable for the developing countries
'include lather boosters such as alkanolamides, particularl~ '
the monoethanolamides derived from palm kernel fatty acids ' '
and coconut fatty acids~ antiredeposition agents such as ~'
sodium carboxymethylcellulose, alkaline buffers such as
sodium silicate, fluorescent agents, perfumes and
colourants and the like.
It is particularl~ preferred to have present an
inorganic filler salt to provide the compositions with
sufficient bulk at an acceptable~cost. ~he amount of the -'
filler salt is from about 5% to about 50%, preferably
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- 9 - G.1046
about 15% to about 40%~ by weight of the composition.
~hese filler salts are generally considered to be inert
materials, although in the case o~ -the soluble salts
such as sodium sulphate there can be some small e~fect
on detergency due to their influence on the ionic
concentration. When any insoluble filler materials are
used such as calcium carbonate, it is important -to have
them as ~inely divided as possible so as not to cause undue
deposition on the fabric being washed. ~xamples of other
suitable inorganic fillers are boraxg magnesium silicate,
talc, calcium sulphate, sodium aluminosilicate and
bentonite or other clays.
As alkali metal carbonate salts function as detergency
builders by precipitation of their insoluble calcium salts,
and the pyrophosphates can sometimes also ac-t in this way,
it can be advantageous to include an amount of an anti-
deposition aid to inhibit deposition of such insoluble
salts on the fabrics. lhe most effective antideposition
aids are anionic polyelectrolytes, especiall~ polymeric
aliphatic carboxylates, for example alkali metal or
ammonium, eg sodium, salts of homo- and~co-pol~mers of
acrylic acid or substituted acrylic acids. ~he amo~mts of
any such antideposition aids is normally from about 0~05% -
to about 5% by weight, preferably from about 0.1% to
25~ about 2% by weight, of the compositions However,-as such
polymeric additives tend to be~relatively expensive they
are preferabl~ used, if at all, at low-levels within this
range in the compositions of the invention~ -
Some soap may also be included in~the co~positions of
the invention but not as the sole detergent surfactant.In general the soaps are relatively expensive and i~ used
at only low levels the~ can have an undesirable suds
depressing action.- ~owever, in some countries soap may be
~more widely available than imported synthetic detergent
surfactants in which case ~ Q~oportion ot soap ma~ be used,
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prePerably not exceeding about half of the total
surfactant present.
~ he compositions of the invention are re~uired to be
alkaline, but not -too strongly alkaline as this could
result in fabric damage and also be hazardous ~or use,
- especially in manual washing. It is desired in practice
that the composition should give a p~ of from about 9 to 11
in use in a~ueous wash solution, preferably from about
9.5 to 10.5, as measured at a product concentxation of about
0.1% w/v in water of 12H (Ca) at 25C~ ~he pH of the
detergent compositions in use is controlled in particul æ
by the amount of the alkali metal carbonate salt present
a~d on any other alkaline salts which may be used, especially
alkali metal silicate.
Ap æt from its effect on pH control, the presence in
the detergent compositions of an àmount of an alkali~metal
silicate is generally advantageous in facilitating processing
of the detergent compositions and giving generally improved
powder properties. ~he t~pe of alkali metal~`silicate used
is preferably sodiu~ silicate, for example sodium ortho-,
meta- or preferabIy neutral or alkaline silicate. ~he
more highly alkaline ortho- and meta silicates are normally
only used at lower levels, in admix*ure with neutral or
alkaline silicates.
~he detergent compositions of the invention are
requirèd to be in particulate form, which includes powders
` and granules and they may be made by conventional techniques,
for example by granulation or by slurry making and spray
drying processes, so as to give substantially homogenous
products. ~he pyrophosphate may be post-dosed to the
composition. ~lternatively~ they may be in -t~e form of
laundry bars which may~be formed ~b~ con~entional methods
such as mixing and extruding.
~ The invention is illustrated by the following ~xamples
in which parts and percentages are by weight`and in which
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- ~1 - C.1046
the amounts o~ the in~redients are expressed on an
anhydrous basis, except where otherwise indicated.
EXAMPIES 1 ~0 4
Six powdered detergen-t compositions including two
co~trol products A and B were prepared as follows:
%
A Ex 1 Ex 2 B Ex ~ Ex
~odium alk~l benzene 28 28 ` 28 28 28 28
sulphonate
Sodium pyrophosphate 8 8 8 4.` `4 4
Sodium carbonate 0 10 20 0 15 30
Sodium alkaline
silicate -~ - 10Ø
Sodium sulphate . 44 34 2~ 48 33 18
Water ; -- ~ to 100
Each o~ these compositions was then added to water o~
;n;tially 30~ H (Ca) at 25G, the product dosage being
~.5 g/l. ~he ~ree calcium ion concentrations were -then
determined at intervals, with the following results-
Comp ~ime: Initiall~ ~ min 1 min 2 mins 4 mins 15 mins
A
A `301311.5 11.5 11~5 ~ 11
~x 1 30 5.~ 5.~-7 4~9 5.2 .
~x 2 30 ~1~75 1.6 1.. 7 1.6 1.7
B 30 21.5 20 20 . 19 ~ 17
~x 3 .`30~ 9.0 7.8 7.8 7.6. ` .7.0
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25 ~ 30 ~ 2.7 2.3 2.3 ~2.2 ` 2.0
~he compositions were then tested for detergency using a
product concentration of 2.5 g/l, calcium hardness o~ 15~ `
(French), liquor to cloth ratio of 5:1 and temperatùre of
25 a. ~h~ee.artificially soiled test cloths were used and ~
the-detergency found by determlning the change in light .- ~.
re~lectance before and after washing, with the ~ollowing~
results~
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- 12 - C.1046
Deter~_ncy~ ~Increase in light reflectance)
Composition ~est Cloth A Test ~loth B ~est Cloth C
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A 26.7 801 19.5
~x 1 27.L~ 9~5 21.0
~x 2 29.5 10.0 22.0
B 22.6 5.7 17.0
~x 3 26.5 ~o6 19~0
Ex 4 28.5 7.6 20~0
~hese results show a marked benefit in water
so~tening properties and hence detergency for the
compositions made according to the invention, especially
with the higher carbonate levels.
XAMPIE 5 :
~o detergent compositions were prepared to the
15 ~ollowing ~ormulations: ` `
%
Ingredient Example 5 Product C
Sodium alkyl benzene sulphonate 25 25
Sodium pyrophosphate 7.5
20 Sodium c æbonate . ~ 15 ~ 30
Sodium alkaline silicate ~ 10 10
Sodium sulphate ~ 26.5 19.0
Sodium carboxy ~ethyl cellulose 0.5 0~5
Water : to 100to 100 -
.~he compositions were then tested ~or detergency
b~ the procedure as used in Examples 1 to 4, with the
following results:
Detergenc~ ~ e n light re lectance
Composition est Cloth A est Cloth B ~ ~est Cloth a
~xample 5 ~ ~5.9 - - 24.5 -11.1 -:~
Product C . 28.3 - -20.2 - ~.2 .:`
~he benèfit of using a low pyrophosphate level with the
sodium carbonate builder in the~composition of the~invention
~ is readily apparent, compared with the control produc-t C
which had a higher level of sodium carbonate as the builder~
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E~AMPL~S 6 ~0 8
~he following ~ormulations, including three controls
D to ~, were prepared:
%
5 In~redient Ex 6 -D E ~_Z ~ ~ 8
Sodium alkyl
benzene sulphonate 28 28 28 28 28 28
Sodium pyrophosphate 10 - 10 12 - 10
Sodium carbonate .30 30 - 30 10 10
Sodium percarbonate' - - - - 29.6 29.6
10 Sodium silicate 10 10 10 10 10 10
Sodium sulphate - 12 22 42 10 12.4 2.
Water - to 1'00`
~ he detergency perfomance of these compositions was
investigated at product concentrations Q~ 2.5 g/l, calcium
hardness of 15X (~rench), liquor to cloth ratio o~ 5:1
and a temperature of 25G ~hree artificially soiled
test cloths were used and the detergency found b~ .
determining the change in.light reflectance be~ore and
after washing, with the ~ollowing results:
20èst Cloth (Increase in lig~t reflectance~ : .'
ormulat _n ~est'al~th`'A .. ';;` est Cloth ~ est Cloth C
~x 6 ~ 35-6 ~ ~ 25~5 ' .16.8
D :27~4 . 21.1 10.1
' ~ ~ 31.2 ~ 22.2 : 13.4`:
EX 7 . ' 35.1 ~ - 24.8~ 16.5
28.0 .~ ~ 20.4 ~ '~ . 9.0
Ex 8 ' -' . .36.2 ~ 24.8~ 15-7
. Ihe test'cloths`~us.ed''i~Example 2 to~'8 were as-`'~ollo~s~
` est Cloth A -~A mixture of sebum fatt~'acids and:carbon
black impregnated into cotton-poplin.
~est Cloth B - A mixture-of ground nut oil, indian ink~
`~ casein and iron oxide~impregnated into cotton sheet m g.
~: Iest Cloth C - A mixture o~ band~ black cla~, a nonionic
detergent and a cationic~detergent impregnated~'into
cotton cIoth.
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~ he performance of the for~ulations of Examples 6 and
8 was investigated at 60C, the other test conditions
remaining the same, except that the test cloth was a
tea stained cloth. ~he results were as ~ollows:
ormulation , Change in re~lectance
~x 6 . 0.3
Ex 8 5.2
~XAMPI~ 9
Detergent b æs were prepared according to the
following formulations:
n~redient %
Ex 9 Control G Control H
Sodium alkyl
benzene sulphonate 28 28 28
~odium pyrophosphate 4 - - ~ 16
Sodium carbonate . 22 22 10
Calcite ` 34 35 " :32.4
Sodium sulphate 6 5 6~5
Water . 6 10 7.1 .
~he-bars were used to hand wash Iest Cloth a
(referred to above) at a liquor to cloth ratio o~ 5:1,
water hardness of 15H (~rench) and a wash temperature
o~ 25C. The results were: ~ .
Formulation - ~Change in reflectance
~x 9 ` 11.2
G ~7.2 : .
H - ` : ~ 12.4 ;~
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